So how do you improve upon the already awesome CM36 series? Work with motor guru Steve Neu to change the motor from a slotless design to one with a 1.4 inch diameter slotted stator. Then change the single neodymium rotor magnet from a 2 pole donut to a 4 magnet, four pole rotor for more torque. Throw in better manufacturing, high quality bearings and a removable end bell and you have the new 1406 series of high performance motors from Castle. The end result is an all new motor that cranks out 30% more torque with all the efficiency and endurance that Castle is known for. These motors are bolt in upgrades for most all 1/10 applications and come in the now-standard ratings of 4,600kv, 5,700kv, 6,900kv and 7,700 kv for easy transition for dealers and customers alike.